You are in browse mode. You must login to use MEMORY

level: SEROTONIN RECEPTORS

Questions and Answers List

level questions: SEROTONIN RECEPTORS

Question	Answer
 This is the MOST EXTENSIVELY DISTRIBUTED OF ALL 5-HT RECEPTORS. In CNS, these receptors are present in high density in cerebral cortex, hippocampus, septum, amygdala, but they are proven in small amounts in basal ganglia and thalamus as well.  They are involved in the INHIBITION OF DISCHARGE OF NEURONS, regulation of production of behavior and eating.  They play an important role in the EMERGENCE OF ANXIETY.  They also exert some effects on CV system.	5-HT1A Receptors
 They are present in CNS where they INDUCE PRESYNAPTIC INHIBITION and behavioural effects. They exhibit vascular effects as well, such as pulmonary vasoconstriction. o Discovery of antimigraine properties of Sumatriptan (non-selective 5-HT1D/1B agonist) increased intrest in this sub type of receptors.  Expression of 5-HT1D receptor is very low as compared to 5-HT1B and their clinical significance still largely unknown.  The function of 5-HT1E receptor is unknown but it is hypothesized that they are involved in regulation of memory.  5-HT1F receptor has possible role in vascular contraction. Distribution in brain appears limited.	5-HT1B Receptors
5-HT2 Receptors This class has 3 sub types:	5-HT2A, 5-HT2B, 5-HT2C
This receptor type is EXPRESSED IN MANY CENTRAL AND PERIPHERAL TISSUES. This subtype show INCREASED PLATELET AGGREGATION and INCREASED CAPILLARY PERMEABILITY following exposure to serotonin. In CNS, these receptors are mainly present in basal ganglia. these antagonist are BEING DEVELOPED FOR THE TREATMENT OF SCHIZOPHRENIA.	5-HT2A Receptors
Activation of this receptors LEADS TO THE CONTRACTION OF SMOOTH MUSCLE OF FUNDUS. Direct injection of selective agonist BW723C86 in amygdala have anxiolytic effects in rats. ANTAGONIST OF THESE RECEPTORS ARE RELATIVELY NEW and may FIND CLINICAL APPLICATION IN THE TREATMENT AND PREVENTION OF MIGRAINE.	5-HT2B Receptors
These receptors may found in HIPPOCAMPUS AND SUBSTANTIA NIGRA. Due to lack of selective ligands for these receptors the knowledge of its action remains unclear.	5-HT2C Receptors
With the exception of the 5-HT receptor, a ligand- gated ion channel, all other serotonin receptors are G protein-coupled receptors that activate an intracellular second messenger cascade to produce an excitatory or inhibitory response. The 5-HT receptor antagonist SUPPRESS VOMITING AND NAUSEA by inhibiting serotonin binding to the 5-HT receptors.	5-HT3 Receptors
These receptors are FOUND ON CNS AND MYENTERIC NEURONS. Prucalopride (brand name Resolor, developed by Johnson & Johnson) is a drug acting as a selective, high affinity 5-HT receptor agonist which TARGETS THE IMPAIRED MOTILITY ASSOCIATED WITH CHRONIC CONSTIPATION, thus normalising bowel movements.	5-HT4 Receptors
Rodents have been shown to possess two functional of these receptors subtype. Pharmacological function of these receptors is unknown. Based on their localization, it has been speculated that they MAY BE INVOLVED IN MOTOR CONTROL, ANXIETY, LEARNING, ADAPTIVE BEHAVIOUR AND BRAIN DEVELOPMENT.	5-HT5 Receptors
The exact clinical significance of these receptors remain still unclear. Selective antagonist of this type of serotonin receptor has an impact on behaviour and seem to IMPROVE THE SPATIAL MEMORY of laboratory animal.	5-HT6 Receptors
these receptors are expressed abundantly in the vessels and are RESPONSIBLE FOR PERSISTANT VASODILATION OF ANESTHESIZED EXPERIMENTAL ANIMAL. these receptors are also expressed in CNS and in smooth muscles (in GIT tract).	5-HT7 Receptors